Gastrointestinal Infection: What is it? Types, Causes, Symptoms, Diagnosis, Treatment and Prevention

Refers to viral, parasitic, or bacterial infections that cause gastroenteritis.

Gastroenteritis is a gastrointestinal infection, also known as infectious diarrhea, it is inflammation of the gastrointestinal tract that affects the stomach and small intestine.

Fever, lack of energy, and dehydration can also occur. This typically lasts less than two weeks. It is not related to influenza, although it has been called the “stomach flu.”

Gastroenteritis can be caused by infections from viruses, bacteria, parasites, and fungi. In children, rotavirus is the most common cause of serious illness. In adults, norovirus and Campylobacter are common.

Tests to confirm the diagnosis are generally not necessary. Prevention includes washing hands with soap, drinking clean water, disposing of human waste, and breastfeeding babies instead of using formula.

For more severe cases, intravenous fluids may be needed. Fluids can also be given through a nasogastric tube. Zinc supplementation is recommended in children.

In 2015, two billion cases of gastroenteritis caused 1.3 million deaths worldwide. Children and those in the developing world are the most affected. In 2011, approximately 1.7 billion cases resulted in approximately 700,000 deaths of children under the age of five.

Repetitive infections are generally seen in areas with poor sanitation, and malnutrition, growth retardation, and long-term cognitive delays can occur .

Rotavirus, norovirus, adenovirus, and astrovirus are known to cause viral gastroenteritis. Rotavirus is the most common cause of gastroenteritis in children and produces similar rates in both the developed and developing world.

Gastrointestinal infections play a particularly important role in inducing a compromise in the nutritional status of the host.

Malabsorption in gastrointestinal diseases can be the result of epithelial destruction of the pathogen or, alternatively, of the immune response to the pathogen.

Even common diarrheal illnesses can have a profound impact on nutrient absorption.

In symptomatic rotavirus infection, the most common cause of acute diarrheal disease worldwide, there is a 42% decrease in nitrogen and fat absorption, a 48% decrease in carbohydrate absorption, and a 55% decrease in total energy absorption.

These rates of malabsorption are slightly more severe in both enterotoxigenic Escherichia coli and shigellosis infections .

In shigellosis, the loss of protein is considerable and important and vitamin A is wasted. Giardiasis and ascariasis lead to malabsorption of vitamin A. Large losses of zinc occur in diarrhea.

Gastrointestinal infections are the most common illnesses in travelers, occurring in 34% of all travelers, typically those traveling from high-income to low- and middle-income countries.

Traveler’s diarrhea (TD) is defined as three or more unformed stools per day and at least one additional gastrointestinal symptom, such as nausea, vomiting, and abdominal pain, and possibly systemic findings including fever and malaise. .

Most traveler’s diarrhea is commonly attributed to enterotoxigenic Escherichia coli (ETEC) strains and occurs within the first 2 weeks of travel with a mean duration of 4-5 days.

Since most patients travel for at least 1 week, a healthcare provider will rarely see a case of recent-onset diarrhea in a returning traveler.

In contrast, most cases of travel-acquired diarrhea seen by the medical facility will be prolonged or recurrent.

Approximately 10% of patients with traveler’s diarrhea will experience symptoms for more than 1 week, and in 5-10%, symptoms will last 2 weeks or more.

It is normal to have food poisoning from time to time. But food poisoning is not chronic, and it usually has a time limit, so if you have an all too frequent bout of food poisoning , it’s important to see a doctor about your symptoms.

What is viral gastroenteritis?

Also known as the stomach flu, viral gastroenteritis affects people all over the world.

This highly contagious disease is spread through close contact with people who are infected or through contaminated food or water. It can easily spread in tight spaces, such as:

Child care facilities, schools, nursing homes, and cruise ships.

Different viruses can cause the disease, each with its own peak season. The most common viruses include norovirus and rotavirus.

There are steps you can take to lower your chances of catching the viruses that cause viral gastroenteritis. These include frequent hand washing and avoiding contaminated water and food products.

What Causes Viral Gastroenteritis?

Viral gastroenteritis is caused by several different viruses. People most at risk are:

Children under 5 years old, older adults, especially if they live in nursing homes, children and adults with compromised immune systems.

It is easy for this virus to spread in group situations. Some of the ways the virus is transmitted include:

Inadequate hand washing, especially by food handlers, sewage contaminated water, consuming raw or undercooked shellfish from contaminated waters

Learn more about the individual viruses that can cause the condition.


Norovirus is highly contagious and can affect anyone at any age. It is spread through contaminated food, water, and surfaces, or by people who have the virus.

Norovirus is common in crowded spaces. Symptoms include:

Nausea, diarrhea, fever and pain in the body. According to the Centers for Disease Control and Prevention (CDC), most people with norovirus feel better within one to three days after experiencing symptoms.

Most outbreaks in the United States occur between November and April.


Rotavirus commonly affects infants and young children. They can then spread the infection to other children and adults. It usually contracts and spreads through the mouth. Symptoms generally appear within two days of infection and include:

Vomiting, loss of appetite, and watery diarrhea that lasts three to eight days. According to the Centers for Disease Control, this virus is most common between the months of December and June.

In 2006, the infant rotavirus vaccine was approved. Early vaccination is recommended to prevent serious rotavirus illness in infants and young children.


It can cause several conditions, including gastroenteritis. You get adenovirus through the air through sneezing and coughing, touching contaminated objects, or touching the hands of someone with the virus. Symptoms associated with adenovirus include:

Sore throat, pink eye , fever, cough, and runny nose. Children in daycare, especially those 6 months to 2 years, are more likely to get adenovirus.

Most children will feel better within a few days of experiencing adenovirus symptoms. However, symptoms like pink can take longer to go away.


Astrovirus is another virus that commonly causes gastroenteritis in children. Symptoms associated with astrovirus include:

Diarrhea, headache, mild dehydration, and stomach pain. The virus generally affects people in late winter and early spring. It is passed through contact with a person who has the virus or an infected surface or food.

Symptoms usually appear two to three days after initial exposure, and the virus usually clears up within two to three days.

What are the symptoms of viral gastroenteritis?

Symptoms of gastroenteritis usually begin a day or two after infection and include:

Diarrhea, nausea and vomiting, headache, muscle aches or joint pain, fever or chills, clammy or clammy skin, abdominal cramps and pain, loss of appetite. These symptoms can last from 1 to 10 days.

You should seek emergency medical treatment if the diarrhea has lasted three days or more without being less frequent, blood is present in your diarrhea, you show or see signs of dehydration, such as dry lips or dizziness.

In addition to the above symptoms, you should seek emergency care for your child if they have the appearance of sunken eyes.

What conditions can look like viral gastroenteritis?

Sometimes other factors can cause symptoms that closely resemble viral gastroenteritis. These causes include:

Food intolerance: Examples of common food intolerances include lactose, fructose, and artificial sweeteners.

Digestive disorders : These include inflammatory diseases such as Crohn’s disease , ulcerative colitis , irritable bowel syndrome, or celiac disease.

Certain Medications : Antibiotics or antacids with magnesium can cause stomach flu-like symptoms.

If your symptoms do not improve in two to three days, you should see your doctor.

What are the complications of viral gastroenteritis?

The main complication of viral gastroenteritis is dehydration, which can be quite serious in infants and young children. Other complications include:

Nutritional imbalances, muscle weakness. Dehydration can be life threatening.

Call your doctor if you or your child have these symptoms:

Diarrhea that lasts more than a few days, blood in your stool, confusion or lethargy, feeling weak or dizzy, nausea, dry mouth, an inability to produce tears, no urination for more than eight hours, or urine that is dark yellow or brown in color , sunken eyes and sunken fontanel on a baby’s head.

The dehydration that can accompany viral gastroenteritis can lead to several complications of its own. These include:

Swelling of the brain, coma, hypovolemic shock, a condition that occurs when your body does not have enough fluid or blood, and  kidney failure .

To prevent complications, you should seek immediate medical attention if you or your child have symptoms of dehydration.

How is viral gastroenteritis diagnosed?

Most of the time, a medical history and physical exam are the basis of the diagnosis, especially if there is evidence that the virus is spreading through your community.

Your doctor may also order a stool sample to test for the type of virus or to determine if your illness is caused by a parasitic or bacterial infection.

How is viral gastroenteritis treated?

The main goal of treatment is to prevent dehydration by drinking plenty of fluids. In severe cases, hospitalization and intravenous fluids are necessary.

Over-the-counter oral rehydration solutions (OHS), such as Pedialyte, can be helpful in mild cases.

Oral rehydration solutions are made to be easy on your child’s stomach and contain a balanced mix of water and salts to replenish essential fluids and electrolytes. These solutions are available at local pharmacies and do not require a prescription. However, you must follow the instructions carefully.

Buy oral rehydration solutions like Pedialyte. Buy oral electrolyte products.

What to eat and what to avoid

As you begin to feel better and reintroduce foods into your diet, it is generally best to opt for bland foods. These foods include:

Rice, potatoes, toast, bananas and coba. These foods are easier to digest and less likely to cause additional stomach upset.

Until you feel better, you may want to avoid certain items, such as high-fat foods, caffeine, alcohol, sugary foods, and dairy products.

Self-care steps

If you have viral gastroenteritis, there are some self-care steps you can take.

Drink extra fluids with and between meals. If you are having difficulty, try drinking very small amounts of water or sucking on ice chips. Avoid fruit juices as they do not replace minerals and can actually increase diarrhea.

Children and adults can use sports drinks to replenish electrolytes. Younger children and infants should use products formulated for children, such as over-the-counter oral rehydration solutions.

Eat food in small amounts and let your stomach recover. Get plenty of rest. You may feel tired or weak.

Check with your doctor before taking medicine or giving it to children. Never give aspirin to children or teens with a viral illness. This can cause Reye’s syndrome, a life-threatening condition.

What natural and home remedies are effective against viral gastroenteritis?

In addition to rehydrating and resting, there are some natural and home remedies that can help relieve viral gastroenteritis.

Heating pad or heat pack

Try applying a low-temperature heating pad or a warm heating pack to your stomach to ease cramps. Cover the heating pad with a cloth and do not leave it on for more than 15 minutes at a time.

Integral rice

Some parents serve their child rice water. This is the water that remains after boiling brown rice. It is high in electrolytes and can help rehydrate, as can over-the-counter oral rehydration solutions. Chill the rice water before serving.


Products that contain ginger, such as ginger ale or ginger tea, can help calm an upset stomach.


Peppermint may also have anti-nausea properties similar to ginger. Drinking a mild peppermint tea can help you feel better.

Yogurt or kefir

Although dairy products should be avoided when you have the most acute symptoms, eating plain yogurt with live active cultures or drinking kefir can help restore your body’s natural bacterial balance after illness.

What is the long-term outlook?

Viral gastroenteritis usually resolves without medical treatment within two to three days. Most people make a full recovery with no long-lasting side effects.

How can viral gastroenteritis be prevented?

Viral gastroenteritis spreads easily. There are some things you can do to reduce your chances of getting the virus or spreading it to others.

Wash your hands often, especially after using the bathroom and before preparing food. If necessary, use hand sanitizer until you can access soap and water.

Don’t share kitchen utensils, dishes, or towels if someone in your home is sick. Don’t eat raw or undercooked foods. Wash fruits and vegetables well.

Take special precautions to avoid contaminated water and food when traveling. Avoid ice cubes and use bottled water whenever possible.

Ask your doctor if you should vaccinate your baby against rotavirus. There are two vaccines, and they usually start around 2 months of age.

What is bacterial gastroenteritis?

Bacterial gastroenteritis occurs when bacteria cause an infection in the intestine. This causes inflammation in your stomach and intestines. You may also experience symptoms such as vomiting, severe abdominal cramps, and diarrhea.

While viruses cause many gastrointestinal infections, bacterial infections are also common. Some people call this infection “food poisoning.”

Bacterial gastroenteritis can be the result of poor hygiene. Infection can also occur after close contact with animals or consuming food or water contaminated with bacteria (or the toxic substances that bacteria produce).

Symptoms of bacterial gastroenteritis

The symptoms of bacterial gastroenteritis vary depending on the bacteria causing the infection. Symptoms can include:

Loss of appetite, nausea and vomiting, diarrhea, abdominal pain and cramps, blood in your stool, and fever.

Call your doctor if your symptoms do not improve after five days (two days for children). If a child older than three months continues to vomit after 12 hours, call a doctor. If a baby less than three months old has diarrhea or vomiting, call your doctor.

Bacterial gastroenteritis treatment

The treatment is intended to keep you hydrated and avoid complications. It is important not to lose too much salt, such as sodium and potassium. Your body needs these in certain amounts to function properly.

If you have a severe case of bacterial gastroenteritis, you may be admitted to the hospital and given fluids and salts through an IV. Antibiotics are generally reserved for the most severe cases.

Home remedies for mild cases

If you have a milder case, you may be able to treat your condition at home. Try the following:

Drink fluids regularly throughout the day, especially after bouts of diarrhea. Eat little and often, and include some salty foods. Consume foods or drinks with potassium, such as fruit juice and bananas.

Do not take any medications without consulting your doctor. Go to the hospital if you can’t keep fluids down.

Some of the ingredients that you can have at home can help keep your electrolytes balanced and treat diarrhea. Ginger can help fight infection and make stomach or abdominal pain less severe.

Apple cider vinegar and basil can also calm the stomach and strengthen the stomach against future infections. Avoid eating dairy, fruit, or high-fiber foods to prevent diarrhea from getting worse.

Over-the-counter medicines that neutralize your stomach acid can help fight these infections. Medicines that treat symptoms such as diarrhea, nausea, and abdominal pain can help relieve the stress and pain of infection. Don’t take over-the-counter treatments unless your doctor tells you to.

Causes of bacterial gastroenteritis

Numerous bacteria can cause gastroenteritis, including:

Yersinia, found in pork, Staph, found in dairy, meat, and eggs, Shigella, found in water (often pools), Salmonella, found in meat, dairy, and eggs.

Campylobacter, found in meat and poultry, E. coli, found in ground beef and salads.

Bacterial gastroenteritis outbreaks can occur when restaurants serve contaminated food to many people. An outbreak can also trigger recalls of produce and other foods.

Bacterial gastroenteritis can be easily spread from person to person if someone carries the bacteria on their hands. Every time a person infected with this bacteria touches food, objects or other people, they run the risk of transmitting the infection to others.

You can even cause the infection to enter your own body if you touch your eyes, mouth, or other open parts of your body with infected hands.

You are especially at risk for these infections if you travel a lot or if you live in a crowded area. Washing your hands frequently and using hand sanitizer with more than 60 percent alcohol can help you avoid getting infections from those around you.

Preventing bacterial gastroenteritis

If you already have gastroenteritis, take safety precautions to avoid spreading the bacteria to others.

Wash your hands after using the bathroom and before handling food. Don’t prepare food for other people until your symptoms improve. Avoid close contact with other people during your illness.

After your symptoms stop, try to wait at least 48 hours before returning to work.

You can also help prevent bacterial gastroenteritis infections by avoiding unpasteurized milk, raw meat, or raw seafood. Use cutting boards and utensils for raw and cooked meats when preparing meals.

Wash salads and vegetables well. Make sure to store food at very hot or very cold temperatures if you are storing it for more than a couple of hours.

Other preventive measures include:

Keeping your kitchen constantly clean, washing your hands after using the bathroom, before handling different foods, after handling animals and before eating, drinking bottled water while traveling abroad, and getting recommended vaccinations:

Risk factors for bacterial gastroenteritis

If you have a weak immune system due to an existing condition or treatment, you may be at increased risk for bacterial gastroenteritis. The risk also increases if you take medications that decrease heartburn.

Handling food incorrectly can also increase your risk of bacterial gastroenteritis. Food that is undercooked, stored too long at room temperature, or not reheated properly can help bacteria spread and survive.

Bacteria can produce harmful substances known as toxins. These toxins can remain even after food is reheated.

Bacterial gastroenteritis diagnosis

Your doctor will ask you questions about your condition and check for signs of dehydration and abdominal pain. To find out which bacteria is causing your infection, you may be asked to provide a stool sample for testing.

Your doctor may also take a blood sample to check for dehydration.


Bacterial gastroenteritis infections rarely cause complications in healthy adults and generally last less than a week.

Older adults or very young children are more vulnerable to the symptoms of gastroenteritis and have a higher risk of complications. These people should be closely monitored as they may need medical attention.

Complications from these infections include a high fever, muscle pain, and an inability to control your bowel movements. Some bacterial infections can cause kidney failure, bleeding in the intestinal tract, and anemia.

Some serious infections that are not treated can cause brain damage and death. Seeking treatment quickly for bacterial gastroenteritis lowers the risk of these complications.

Bacterial gastroenteritis in children

Children may be more prone to bacterial gastroenteritis infections than adults. For example, a 2015 report states that children in the United States under the age of one are more likely to contract salmonella.

Most Salmonella infections occur when children consume contaminated food or water or come into contact with animals that carry the bacteria.

Young children are also more likely to get Clostridium difficile infections. These bacteria are mainly found in dirt and animal feces.

Children are more likely to develop infections from these types of bacteria. However, like adults, children are susceptible to any bacterial infection.

Make sure your child practices good hygiene, washes his hands regularly, and avoids putting dirty hands in his mouth or near his eyes. Wash your hands after changing your child’s diaper.

Wash and prepare food thoroughly, cooking raw dishes like eggs, vegetables, and meat until well done.

Many symptoms of bacterial infection in children are the same as symptoms in adults. Young children are especially prone to diarrhea, vomiting, and fevers.

A unique symptom of children with these infections is a dry diaper. If your child has not needed a diaper change for more than six hours, he may be dehydrated.

Talk to your doctor right away if your child has any of these symptoms. If your child has diarrhea or other related symptoms, make sure they drink plenty of fluids.

Recovery and perspective

After seeking treatment or medical attention, get enough rest to help your body fight the infection. If you have diarrhea or vomiting, drink plenty of fluids to stay hydrated.

Do not eat dairy products or fruits to avoid making your diarrhea worse. Sucking on ice cubes can help if you can’t hold onto food or water.

Outbreaks of these bacterial infections can occur in foods sold in many grocery stores. Stay up-to-date with news about public outbreaks of bacteria in certain types of food.

Bacterial gastroenteritis infections generally last one to three days. In some cases, infections can last for weeks and be harmful if left untreated.

Seek treatment as soon as you show symptoms of an infection to prevent the infection from spreading. With good medical care and proper treatment, your infection will likely clear up in a few days.